Improvement in cut-off valve-gear for steam-engines



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C. W. WAILEY, OF NEW ORLEANS, LOUISIANA, ASSIGNOR TO THE NEW ORLEANSPNEUMATIC-PROPELLING COMPANY.

Letters Patent No. 82,184, dated September 15, 1868.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, C. W. WAILEY, of the city of New Orleans, parish ofOrleans, and State of Louisiana, have invented a certain new, useful,and improved Cut-Off Valve for Steam and Pneumatic Engines, or, moreproperly, a new and improved method of operating the valves of suchengines; and I do hereby declare the following to be a full, clear, andexact description of the same, reference being had to the annexeddrawings, making a part of this specification.

The object of my invention is to utilize or make practicably availablethe whole power or force that results from the principle of expansion,and to avoid friction, and the consequent abrasion and wear of thecontiguous surfaces of the valves and their seats. But, before I enterupon a detailed description of my invention, it is proper to remark thatin order to make the whole force of the expansivepower of steam orcompressed atmosplieric air available, either in a steam or in apneumatic engine, the receiving or the induction-valves of the cylindershould be made to open wide enough to admit the steam or compressed air,as the case may be, between the head of the cylinder and the follower,or head of the piston, in sufiicient volume to fill the space thereincontained, at a density or pressure equal to the pressure that obtainsin the generator, or the reservoir or tank in which the atmospheric airis contained and compressed, and to close the moment the piston hastravelled far enough on its stroke to increase the space sufiiciently tohold enough of the motor to finish the stroke by its power of expansion,independently of other air or force. In all existing valves, butespecially in slide-valves, the opening and closing operation isgradual, and hence it is impossible to obtain" apressure on the pistonequal to the pressure in the steam-generator or air-tank, without makingthe openings disproportionately and inconveniently large. The reason ofthis is, that the space is increased by the movement of the piston,whilst the induction is going on as fast as or faster than the inductiontakes place. In fact, as most cylinders are now constructed, it iswholly impracticable to make the openings sufliciently large to secure apressure therein that even approximately equals that which obtains inthe generator or air-tank, and this is the reason Why the full force ofthe elastic or expansive power of the motor has not heretofore beenbrought into use.

My invention remedies this difficulty, for it consists of a mechanicalarrangement or adaption, by which the induction-ports are instantlyopened to their utmost capacity or width, and kept thus open until thepiston has moved upon its stroke far enough to make room between itshead and the head of the cylinder, to admita sntlicient quantity ofsteam or compressed air, as the case may be, to complete the stroke by'the force of its expansion, and then, as suddenly as they were opened,to close the ports, and this, too, without that severe and wearingfriction that is inevitably incident to the operation of every existingvalve of which I have any knowledge. a.

Nor are these the only advantages to which my improvement may justly layclaim. Its use entirely I avoids the waste of the motor, whether thesame be steam or compressed air, which is necessarily involved in thefilling of the long steam-ways that are common to existing engines, forit requires no steam-ways except through the shell of the cylinder, andthese consist of the perfectly-straight ports, through which the motorenters the cylinder. In other words, my invention consists of atogglejoint, which, it is well known, possesses, when its twmsections ormembers are brought into the same straight line', a mechanical powerthat is infinite, or rather of the application of a toggle, or itscombination with the valves of steam or pneumatic engines, in order tooperate them. By the employment of the toggle-joint, I meet all therequisite conditions to produce a perfect valve-motion, by which I meanthe lifting and the pressing down of the same, without any appreciablefriction between the surfaces that come in contact with one another, andhence without any appreciable wear of the same, however prolonged theuse. In fact, there may be said to be no friction or wear in a valvethat is moved by a toggle, excepting only where the stem to which thevalve is attached, passes through its stuffingbox, where its effects maybe remedied very easily, as frequently as necessity shall require.

In applying my invention to practice, it is necessary that theinductionand exhaust-valves should beplaced on opposite sides of the cylinder,and so arranged as to be worked independently of each other, as will bevery clearly manifest after I have explained its nature and operation.

But my invention will be better'and more-quickly understood byreferring-to the drawings, in which front and top views are given, both,however, being in part sectional, the line of bisection being throughthe exhaust or, eduction-valves.

On the drawings, A is a cylinder, it may be either a steam or acompressed-air cylinder, which, inasmuch as I make no claim to havingmade any improvement thereupon or in, is shown as though it is in solidform. From the opposite sides of the cylinder A, project, in the sameaxial line or plane, the arms B B B B', on the outer extremities ofwhich are fitted or placed the adjustable caps O 'CG 0, that are held inposition by screws 0, as shown. To these caps the outer sections or armsof the toggles D D D D are secured, and moved on the pivot-pins at. Andto the rods I,- which'are connected to theinner section of the togglesby mova blejoints, the valves are secured. These rods constitute thestems proper of the valves, which move in right or straight lines,through proper stuiiing-boxes at t. In guide-ways or grooves that arecut transversely across the projecting arms B B B B, are fitted thesliding bars E E. The bar E, on the induction-side of the cylinder, isprovided with a longitudinal-adjusting screw-rod, F, to which the crankG is secured, in order thatit may be rotated in either direction. Thisscrew-rod passes through a fixed centre-piece, H, that has a collar onboth sides ofit, and it is through the agency of this centre-piece thatthe rotation of the rod may-be effected to the right or to the left, andboth ends of the same, with respect to the said centre-piece, beshortened or lengthened at will. J J are movable blocks or stoppers onthe bar E, which, being fitted onscrew-rod F by female-screw threads,aiford the means for adjusting the cut-off at any point at which it maybe desired to make it,'for accordingly-as the screw-rod is turned to theright or to the left, are these stoppers drawn towards or pushed fromthe centre-piece H, and the cut-off effected at ashorter or longerdistance from the induction-valves at the extremities of the cylinder.These stoppers slide in grooves in the bar E, in order to make thismovement, and on their front faces are fixed adjustable plates, that areso formed, that whilst they strike against the pins 0 in the toggles Dand D, and thereby actuate-the said toggles, whilst the bar E moves inone direction, they pass over the said pins without affecting thetoggles when this bar is moving in the other or reverse direction. Areciprocating or backward-and-forward motion is imparted to the bar E,by gearing the same to the main shaft of the machine, or to some otherpart, to which a crank or pulley may be easily alfixed.

The bar E has no adjusting-screw rod corresponding with that connectedwith the bar E, for, being on the eduction-side of the cylinder, andoperating the exhaust-valves, no adjustment of the stoppers connectedthere with is necessary. This bar is connected with the shaft of theengine at the wrist 01, and, through the action of an eccentric placedon said shaft, has a reciprocating motion imparted to it that is nearlycoincident, in the length of its stroke, to that of the piston of thecylinder. This bar E works on the same principle as the bar E, and it isprovided with the same adjuncts, but the stopper-blocks K K are fixed,there being no need of an adjusting-screw rod, F, so as alternately toopen the exhaust-valves at each end of the cylinder to their greatestcapacity, at every stroke of the piston, to allow of the instant escapeof the motor at the instant the returnstroke begins. 4

The operation of my invention is as follows When the piston arrives atthe end of its stroke, the stopper-block J or J, accordingly as thestroke has been in the one or the other direction, strikes, by means ofits face-plate, against the pin cin the toggle D or D, as the case maybe, and by bending the said toggle at its centraljoint from a straightline, as shown at D, lifts the valve connected with it from off itsseat, and permits the steam or compressed air to rush under the saidvalve, which is thereby, by reason of the expansive power'of the same,carried up to the full extent ofits lift, without further aid from thestopper-block, the same, in fact, being relieved from all further dutyof pressing against the pin 0, to operate the valve. The stopper-blocksK K on the bar E, are adjusted in such manner as always to open theeduction-valves at the instant the piston changes its motion to makeareturn-stroke, so as to prevent any resistance thereto by the presenceof steam or air, as the case maybe, in the cylinder.

To illustrate the operation of my invention still more clearly, supposethe stoppers J J'to be so set or adjusted as that the induction of themotor shall continue nearly the whole, or during'nearly the whole strokeof the piston, the stopper J, for example, will have closed the port ofthe valve that is operated by the toggle D, by passing over the pin aprojecting therefrom, but the valve worked by toggle D will be open, andthe induction of the motor will continue until the piston shall havetravelled nearly its whole stroke, because the stopper J will not inthat case be brought into contact with the pin a, projecting from toggleD, and thus close the valve connected with said toggle, until the strokeof the piston is nearly completed. The sliding bar E has always the samestroke, but by moving the stoppenblocks J J, through the agency of thescrew-rod F, the cutofl' may be made at any point, and hence if thecompression of the motor be very, great, as in the case of a pneumaticengine, the expansive force of the same may be made to do nearly all thework of driving the machine. 7

Theadvantages of my invention are that it is simple and yet verypowerful in its action, whilst at the same time it opens and closes avalve with inconceivable rapidity, without appreciable friction or wearof the parts that come in contact with each other.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. The arrangement of the toggle-joints D D D D, with reference to theinduction and eduction-valves, when those parts are constructedsubstantially as herein described.

2. The arrangement of the toggle-joints D D D" D with the bars E and E,substantially as herein described.

. C. W. WAILEY.

Witnesses:

RUFUS R. Rrroons, H. N. JENKINS.

